diff options
Diffstat (limited to 'googlemock/docs/cheat_sheet.md')
| -rw-r--r-- | googlemock/docs/cheat_sheet.md | 786 |
1 files changed, 0 insertions, 786 deletions
diff --git a/googlemock/docs/cheat_sheet.md b/googlemock/docs/cheat_sheet.md deleted file mode 100644 index dc2428e..0000000 --- a/googlemock/docs/cheat_sheet.md +++ /dev/null @@ -1,786 +0,0 @@ -# gMock Cheat Sheet - -<!-- GOOGLETEST_CM0019 DO NOT DELETE --> - -<!-- GOOGLETEST_CM0035 DO NOT DELETE --> - -<!-- GOOGLETEST_CM0033 DO NOT DELETE --> - -## Defining a Mock Class - -### Mocking a Normal Class {#MockClass} - -Given - -```cpp -class Foo { - ... - virtual ~Foo(); - virtual int GetSize() const = 0; - virtual string Describe(const char* name) = 0; - virtual string Describe(int type) = 0; - virtual bool Process(Bar elem, int count) = 0; -}; -``` - -(note that `~Foo()` **must** be virtual) we can define its mock as - -```cpp -#include "gmock/gmock.h" - -class MockFoo : public Foo { - ... - MOCK_METHOD(int, GetSize, (), (const, override)); - MOCK_METHOD(string, Describe, (const char* name), (override)); - MOCK_METHOD(string, Describe, (int type), (override)); - MOCK_METHOD(bool, Process, (Bar elem, int count), (override)); -}; -``` - -To create a "nice" mock, which ignores all uninteresting calls, a "naggy" mock, -which warns on all uninteresting calls, or a "strict" mock, which treats them as -failures: - -```cpp -using ::testing::NiceMock; -using ::testing::NaggyMock; -using ::testing::StrictMock; - -NiceMock<MockFoo> nice_foo; // The type is a subclass of MockFoo. -NaggyMock<MockFoo> naggy_foo; // The type is a subclass of MockFoo. -StrictMock<MockFoo> strict_foo; // The type is a subclass of MockFoo. -``` - -**Note:** A mock object is currently naggy by default. We may make it nice by -default in the future. - -### Mocking a Class Template {#MockTemplate} - -Class templates can be mocked just like any class. - -To mock - -```cpp -template <typename Elem> -class StackInterface { - ... - virtual ~StackInterface(); - virtual int GetSize() const = 0; - virtual void Push(const Elem& x) = 0; -}; -``` - -(note that all member functions that are mocked, including `~StackInterface()` -**must** be virtual). - -```cpp -template <typename Elem> -class MockStack : public StackInterface<Elem> { - ... - MOCK_METHOD(int, GetSize, (), (const, override)); - MOCK_METHOD(void, Push, (const Elem& x), (override)); -}; -``` - -### Specifying Calling Conventions for Mock Functions - -If your mock function doesn't use the default calling convention, you can -specify it by adding `Calltype(convention)` to `MOCK_METHOD`'s 4th parameter. -For example, - -```cpp - MOCK_METHOD(bool, Foo, (int n), (Calltype(STDMETHODCALLTYPE))); - MOCK_METHOD(int, Bar, (double x, double y), - (const, Calltype(STDMETHODCALLTYPE))); -``` - -where `STDMETHODCALLTYPE` is defined by `<objbase.h>` on Windows. - -## Using Mocks in Tests {#UsingMocks} - -The typical work flow is: - -1. Import the gMock names you need to use. All gMock symbols are in the - `testing` namespace unless they are macros or otherwise noted. -2. Create the mock objects. -3. Optionally, set the default actions of the mock objects. -4. Set your expectations on the mock objects (How will they be called? What - will they do?). -5. Exercise code that uses the mock objects; if necessary, check the result - using googletest assertions. -6. When a mock object is destructed, gMock automatically verifies that all - expectations on it have been satisfied. - -Here's an example: - -```cpp -using ::testing::Return; // #1 - -TEST(BarTest, DoesThis) { - MockFoo foo; // #2 - - ON_CALL(foo, GetSize()) // #3 - .WillByDefault(Return(1)); - // ... other default actions ... - - EXPECT_CALL(foo, Describe(5)) // #4 - .Times(3) - .WillRepeatedly(Return("Category 5")); - // ... other expectations ... - - EXPECT_EQ("good", MyProductionFunction(&foo)); // #5 -} // #6 -``` - -## Setting Default Actions {#OnCall} - -gMock has a **built-in default action** for any function that returns `void`, -`bool`, a numeric value, or a pointer. In C++11, it will additionally returns -the default-constructed value, if one exists for the given type. - -To customize the default action for functions with return type *`T`*: - -```cpp -using ::testing::DefaultValue; - -// Sets the default value to be returned. T must be CopyConstructible. -DefaultValue<T>::Set(value); -// Sets a factory. Will be invoked on demand. T must be MoveConstructible. -// T MakeT(); -DefaultValue<T>::SetFactory(&MakeT); -// ... use the mocks ... -// Resets the default value. -DefaultValue<T>::Clear(); -``` - -Example usage: - -```cpp - // Sets the default action for return type std::unique_ptr<Buzz> to - // creating a new Buzz every time. - DefaultValue<std::unique_ptr<Buzz>>::SetFactory( - [] { return MakeUnique<Buzz>(AccessLevel::kInternal); }); - - // When this fires, the default action of MakeBuzz() will run, which - // will return a new Buzz object. - EXPECT_CALL(mock_buzzer_, MakeBuzz("hello")).Times(AnyNumber()); - - auto buzz1 = mock_buzzer_.MakeBuzz("hello"); - auto buzz2 = mock_buzzer_.MakeBuzz("hello"); - EXPECT_NE(nullptr, buzz1); - EXPECT_NE(nullptr, buzz2); - EXPECT_NE(buzz1, buzz2); - - // Resets the default action for return type std::unique_ptr<Buzz>, - // to avoid interfere with other tests. - DefaultValue<std::unique_ptr<Buzz>>::Clear(); -``` - -To customize the default action for a particular method of a specific mock -object, use `ON_CALL()`. `ON_CALL()` has a similar syntax to `EXPECT_CALL()`, -but it is used for setting default behaviors (when you do not require that the -mock method is called). See [here](cook_book.md#UseOnCall) for a more detailed -discussion. - -```cpp -ON_CALL(mock-object, method(matchers)) - .With(multi-argument-matcher) ? - .WillByDefault(action); -``` - -## Setting Expectations {#ExpectCall} - -`EXPECT_CALL()` sets **expectations** on a mock method (How will it be called? -What will it do?): - -```cpp -EXPECT_CALL(mock-object, method (matchers)?) - .With(multi-argument-matcher) ? - .Times(cardinality) ? - .InSequence(sequences) * - .After(expectations) * - .WillOnce(action) * - .WillRepeatedly(action) ? - .RetiresOnSaturation(); ? -``` - -For each item above, `?` means it can be used at most once, while `*` means it -can be used any number of times. - -In order to pass, `EXPECT_CALL` must be used before the calls are actually made. - -The `(matchers)` is a comma-separated list of matchers that correspond to each -of the arguments of `method`, and sets the expectation only for calls of -`method` that matches all of the matchers. - -If `(matchers)` is omitted, the expectation is the same as if the matchers were -set to anything matchers (for example, `(_, _, _, _)` for a four-arg method). - -If `Times()` is omitted, the cardinality is assumed to be: - -* `Times(1)` when there is neither `WillOnce()` nor `WillRepeatedly()`; -* `Times(n)` when there are `n` `WillOnce()`s but no `WillRepeatedly()`, where - `n` >= 1; or -* `Times(AtLeast(n))` when there are `n` `WillOnce()`s and a - `WillRepeatedly()`, where `n` >= 0. - -A method with no `EXPECT_CALL()` is free to be invoked *any number of times*, -and the default action will be taken each time. - -## Matchers {#MatcherList} - -<!-- GOOGLETEST_CM0020 DO NOT DELETE --> - -A **matcher** matches a *single* argument. You can use it inside `ON_CALL()` or -`EXPECT_CALL()`, or use it to validate a value directly using two macros: - -<!-- mdformat off(github rendering does not support multiline tables) --> -| Macro | Description | -| :----------------------------------- | :------------------------------------ | -| `EXPECT_THAT(actual_value, matcher)` | Asserts that `actual_value` matches `matcher`. | -| `ASSERT_THAT(actual_value, matcher)` | The same as `EXPECT_THAT(actual_value, matcher)`, except that it generates a **fatal** failure. | -<!-- mdformat on --> - -**Note:** Although equality matching via `EXPECT_THAT(actual_value, -expected_value)` is supported, prefer to make the comparison explicit via -`EXPECT_THAT(actual_value, Eq(expected_value))` or `EXPECT_EQ(actual_value, -expected_value)`. - -Built-in matchers (where `argument` is the function argument, e.g. -`actual_value` in the example above, or when used in the context of -`EXPECT_CALL(mock_object, method(matchers))`, the arguments of `method`) are -divided into several categories: - -### Wildcard - -Matcher | Description -:-------------------------- | :----------------------------------------------- -`_` | `argument` can be any value of the correct type. -`A<type>()` or `An<type>()` | `argument` can be any value of type `type`. - -### Generic Comparison - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :--------------------- | :-------------------------------------------------- | -| `Eq(value)` or `value` | `argument == value` | -| `Ge(value)` | `argument >= value` | -| `Gt(value)` | `argument > value` | -| `Le(value)` | `argument <= value` | -| `Lt(value)` | `argument < value` | -| `Ne(value)` | `argument != value` | -| `IsFalse()` | `argument` evaluates to `false` in a Boolean context. | -| `IsTrue()` | `argument` evaluates to `true` in a Boolean context. | -| `IsNull()` | `argument` is a `NULL` pointer (raw or smart). | -| `NotNull()` | `argument` is a non-null pointer (raw or smart). | -| `Optional(m)` | `argument` is `optional<>` that contains a value matching `m`. (For testing whether an `optional<>` is set, check for equality with `nullopt`. You may need to use `Eq(nullopt)` if the inner type doesn't have `==`.)| -| `VariantWith<T>(m)` | `argument` is `variant<>` that holds the alternative of type T with a value matching `m`. | -| `Ref(variable)` | `argument` is a reference to `variable`. | -| `TypedEq<type>(value)` | `argument` has type `type` and is equal to `value`. You may need to use this instead of `Eq(value)` when the mock function is overloaded. | -<!-- mdformat on --> - -Except `Ref()`, these matchers make a *copy* of `value` in case it's modified or -destructed later. If the compiler complains that `value` doesn't have a public -copy constructor, try wrap it in `std::ref()`, e.g. -`Eq(std::ref(non_copyable_value))`. If you do that, make sure -`non_copyable_value` is not changed afterwards, or the meaning of your matcher -will be changed. - -`IsTrue` and `IsFalse` are useful when you need to use a matcher, or for types -that can be explicitly converted to Boolean, but are not implicitly converted to -Boolean. In other cases, you can use the basic -[`EXPECT_TRUE` and `EXPECT_FALSE`](../../googletest/docs/primer#basic-assertions) -assertions. - -### Floating-Point Matchers {#FpMatchers} - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------------- | :--------------------------------- | -| `DoubleEq(a_double)` | `argument` is a `double` value approximately equal to `a_double`, treating two NaNs as unequal. | -| `FloatEq(a_float)` | `argument` is a `float` value approximately equal to `a_float`, treating two NaNs as unequal. | -| `NanSensitiveDoubleEq(a_double)` | `argument` is a `double` value approximately equal to `a_double`, treating two NaNs as equal. | -| `NanSensitiveFloatEq(a_float)` | `argument` is a `float` value approximately equal to `a_float`, treating two NaNs as equal. | -| `IsNan()` | `argument` is any floating-point type with a NaN value. | -<!-- mdformat on --> - -The above matchers use ULP-based comparison (the same as used in googletest). -They automatically pick a reasonable error bound based on the absolute value of -the expected value. `DoubleEq()` and `FloatEq()` conform to the IEEE standard, -which requires comparing two NaNs for equality to return false. The -`NanSensitive*` version instead treats two NaNs as equal, which is often what a -user wants. - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------------------------------ | :----------------------- | -| `DoubleNear(a_double, max_abs_error)` | `argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as unequal. | -| `FloatNear(a_float, max_abs_error)` | `argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as unequal. | -| `NanSensitiveDoubleNear(a_double, max_abs_error)` | `argument` is a `double` value close to `a_double` (absolute error <= `max_abs_error`), treating two NaNs as equal. | -| `NanSensitiveFloatNear(a_float, max_abs_error)` | `argument` is a `float` value close to `a_float` (absolute error <= `max_abs_error`), treating two NaNs as equal. | -<!-- mdformat on --> - -### String Matchers - -The `argument` can be either a C string or a C++ string object: - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :---------------------- | :------------------------------------------------- | -| `ContainsRegex(string)` | `argument` matches the given regular expression. | -| `EndsWith(suffix)` | `argument` ends with string `suffix`. | -| `HasSubstr(string)` | `argument` contains `string` as a sub-string. | -| `MatchesRegex(string)` | `argument` matches the given regular expression with the match starting at the first character and ending at the last character. | -| `StartsWith(prefix)` | `argument` starts with string `prefix`. | -| `StrCaseEq(string)` | `argument` is equal to `string`, ignoring case. | -| `StrCaseNe(string)` | `argument` is not equal to `string`, ignoring case. | -| `StrEq(string)` | `argument` is equal to `string`. | -| `StrNe(string)` | `argument` is not equal to `string`. | -<!-- mdformat on --> - -`ContainsRegex()` and `MatchesRegex()` take ownership of the `RE` object. They -use the regular expression syntax defined -[here](../../googletest/docs/advanced.md#regular-expression-syntax). All of -these matchers, except `ContainsRegex()` and `MatchesRegex()` work for wide -strings as well. - -### Container Matchers - -Most STL-style containers support `==`, so you can use `Eq(expected_container)` -or simply `expected_container` to match a container exactly. If you want to -write the elements in-line, match them more flexibly, or get more informative -messages, you can use: - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :---------------------------------------- | :------------------------------- | -| `BeginEndDistanceIs(m)` | `argument` is a container whose `begin()` and `end()` iterators are separated by a number of increments matching `m`. E.g. `BeginEndDistanceIs(2)` or `BeginEndDistanceIs(Lt(2))`. For containers that define a `size()` method, `SizeIs(m)` may be more efficient. | -| `ContainerEq(container)` | The same as `Eq(container)` except that the failure message also includes which elements are in one container but not the other. | -| `Contains(e)` | `argument` contains an element that matches `e`, which can be either a value or a matcher. | -| `Each(e)` | `argument` is a container where *every* element matches `e`, which can be either a value or a matcher. | -| `ElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, where the *i*-th element matches `ei`, which can be a value or a matcher. | -| `ElementsAreArray({e0, e1, ..., en})`, `ElementsAreArray(a_container)`, `ElementsAreArray(begin, end)`, `ElementsAreArray(array)`, or `ElementsAreArray(array, count)` | The same as `ElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, iterator range, or C-style array. | -| `IsEmpty()` | `argument` is an empty container (`container.empty()`). | -| `IsSubsetOf({e0, e1, ..., en})`, `IsSubsetOf(a_container)`, `IsSubsetOf(begin, end)`, `IsSubsetOf(array)`, or `IsSubsetOf(array, count)` | `argument` matches `UnorderedElementsAre(x0, x1, ..., xk)` for some subset `{x0, x1, ..., xk}` of the expected matchers. | -| `IsSupersetOf({e0, e1, ..., en})`, `IsSupersetOf(a_container)`, `IsSupersetOf(begin, end)`, `IsSupersetOf(array)`, or `IsSupersetOf(array, count)` | Some subset of `argument` matches `UnorderedElementsAre(`expected matchers`)`. | -| `Pointwise(m, container)`, `Pointwise(m, {e0, e1, ..., en})` | `argument` contains the same number of elements as in `container`, and for all i, (the i-th element in `argument`, the i-th element in `container`) match `m`, which is a matcher on 2-tuples. E.g. `Pointwise(Le(), upper_bounds)` verifies that each element in `argument` doesn't exceed the corresponding element in `upper_bounds`. See more detail below. | -| `SizeIs(m)` | `argument` is a container whose size matches `m`. E.g. `SizeIs(2)` or `SizeIs(Lt(2))`. | -| `UnorderedElementsAre(e0, e1, ..., en)` | `argument` has `n + 1` elements, and under *some* permutation of the elements, each element matches an `ei` (for a different `i`), which can be a value or a matcher. | -| `UnorderedElementsAreArray({e0, e1, ..., en})`, `UnorderedElementsAreArray(a_container)`, `UnorderedElementsAreArray(begin, end)`, `UnorderedElementsAreArray(array)`, or `UnorderedElementsAreArray(array, count)` | The same as `UnorderedElementsAre()` except that the expected element values/matchers come from an initializer list, STL-style container, iterator range, or C-style array. | -| `UnorderedPointwise(m, container)`, `UnorderedPointwise(m, {e0, e1, ..., en})` | Like `Pointwise(m, container)`, but ignores the order of elements. | -| `WhenSorted(m)` | When `argument` is sorted using the `<` operator, it matches container matcher `m`. E.g. `WhenSorted(ElementsAre(1, 2, 3))` verifies that `argument` contains elements 1, 2, and 3, ignoring order. | -| `WhenSortedBy(comparator, m)` | The same as `WhenSorted(m)`, except that the given comparator instead of `<` is used to sort `argument`. E.g. `WhenSortedBy(std::greater(), ElementsAre(3, 2, 1))`. | -<!-- mdformat on --> - -**Notes:** - -* These matchers can also match: - 1. a native array passed by reference (e.g. in `Foo(const int (&a)[5])`), - and - 2. an array passed as a pointer and a count (e.g. in `Bar(const T* buffer, - int len)` -- see [Multi-argument Matchers](#MultiArgMatchers)). -* The array being matched may be multi-dimensional (i.e. its elements can be - arrays). -* `m` in `Pointwise(m, ...)` should be a matcher for `::std::tuple<T, U>` - where `T` and `U` are the element type of the actual container and the - expected container, respectively. For example, to compare two `Foo` - containers where `Foo` doesn't support `operator==`, one might write: - - ```cpp - using ::std::get; - MATCHER(FooEq, "") { - return std::get<0>(arg).Equals(std::get<1>(arg)); - } - ... - EXPECT_THAT(actual_foos, Pointwise(FooEq(), expected_foos)); - ``` - -### Member Matchers - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------------ | :----------------------------------------- | -| `Field(&class::field, m)` | `argument.field` (or `argument->field` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_. | -| `Key(e)` | `argument.first` matches `e`, which can be either a value or a matcher. E.g. `Contains(Key(Le(5)))` can verify that a `map` contains a key `<= 5`. | -| `Pair(m1, m2)` | `argument` is an `std::pair` whose `first` field matches `m1` and `second` field matches `m2`. | -| `FieldsAre(m...)` | `argument` is a compatible object where each field matches piecewise with `m...`. A compatible object is any that supports the `std::tuple_size<Obj>`+`get<I>(obj)` protocol. In C++17 and up this also supports types compatible with structured bindings, like aggregates. | -| `Property(&class::property, m)` | `argument.property()` (or `argument->property()` when `argument` is a plain pointer) matches matcher `m`, where `argument` is an object of type _class_. | -<!-- mdformat on --> - -### Matching the Result of a Function, Functor, or Callback - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :--------------- | :------------------------------------------------ | -| `ResultOf(f, m)` | `f(argument)` matches matcher `m`, where `f` is a function or functor. | -<!-- mdformat on --> - -### Pointer Matchers - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------ | :---------------------------------------------- | -| `Address(m)` | the result of `std::addressof(argument)` matches `m`. | -| `Pointee(m)` | `argument` (either a smart pointer or a raw pointer) points to a value that matches matcher `m`. | -| `Pointer(m)` | `argument` (either a smart pointer or a raw pointer) contains a pointer that matches `m`. `m` will match against the raw pointer regardless of the type of `argument`. | -| `WhenDynamicCastTo<T>(m)` | when `argument` is passed through `dynamic_cast<T>()`, it matches matcher `m`. | -<!-- mdformat on --> - -<!-- GOOGLETEST_CM0026 DO NOT DELETE --> - -<!-- GOOGLETEST_CM0027 DO NOT DELETE --> - -### Multi-argument Matchers {#MultiArgMatchers} - -Technically, all matchers match a *single* value. A "multi-argument" matcher is -just one that matches a *tuple*. The following matchers can be used to match a -tuple `(x, y)`: - -Matcher | Description -:------ | :---------- -`Eq()` | `x == y` -`Ge()` | `x >= y` -`Gt()` | `x > y` -`Le()` | `x <= y` -`Lt()` | `x < y` -`Ne()` | `x != y` - -You can use the following selectors to pick a subset of the arguments (or -reorder them) to participate in the matching: - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------- | :---------------------------------------------- | -| `AllArgs(m)` | Equivalent to `m`. Useful as syntactic sugar in `.With(AllArgs(m))`. | -| `Args<N1, N2, ..., Nk>(m)` | The tuple of the `k` selected (using 0-based indices) arguments matches `m`, e.g. `Args<1, 2>(Eq())`. | -<!-- mdformat on --> - -### Composite Matchers - -You can make a matcher from one or more other matchers: - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------------------------- | :-------------------------------------- | -| `AllOf(m1, m2, ..., mn)` | `argument` matches all of the matchers `m1` to `mn`. | -| `AllOfArray({m0, m1, ..., mn})`, `AllOfArray(a_container)`, `AllOfArray(begin, end)`, `AllOfArray(array)`, or `AllOfArray(array, count)` | The same as `AllOf()` except that the matchers come from an initializer list, STL-style container, iterator range, or C-style array. | -| `AnyOf(m1, m2, ..., mn)` | `argument` matches at least one of the matchers `m1` to `mn`. | -| `AnyOfArray({m0, m1, ..., mn})`, `AnyOfArray(a_container)`, `AnyOfArray(begin, end)`, `AnyOfArray(array)`, or `AnyOfArray(array, count)` | The same as `AnyOf()` except that the matchers come from an initializer list, STL-style container, iterator range, or C-style array. | -| `Not(m)` | `argument` doesn't match matcher `m`. | -<!-- mdformat on --> - -<!-- GOOGLETEST_CM0028 DO NOT DELETE --> - -### Adapters for Matchers - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :---------------------- | :------------------------------------ | -| `MatcherCast<T>(m)` | casts matcher `m` to type `Matcher<T>`. | -| `SafeMatcherCast<T>(m)` | [safely casts](cook_book.md#casting-matchers) matcher `m` to type `Matcher<T>`. | -| `Truly(predicate)` | `predicate(argument)` returns something considered by C++ to be true, where `predicate` is a function or functor. | -<!-- mdformat on --> - -`AddressSatisfies(callback)` and `Truly(callback)` take ownership of `callback`, -which must be a permanent callback. - -### Using Matchers as Predicates {#MatchersAsPredicatesCheat} - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :---------------------------- | :------------------------------------------ | -| `Matches(m)(value)` | evaluates to `true` if `value` matches `m`. You can use `Matches(m)` alone as a unary functor. | -| `ExplainMatchResult(m, value, result_listener)` | evaluates to `true` if `value` matches `m`, explaining the result to `result_listener`. | -| `Value(value, m)` | evaluates to `true` if `value` matches `m`. | -<!-- mdformat on --> - -### Defining Matchers - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :----------------------------------- | :------------------------------------ | -| `MATCHER(IsEven, "") { return (arg % 2) == 0; }` | Defines a matcher `IsEven()` to match an even number. | -| `MATCHER_P(IsDivisibleBy, n, "") { *result_listener << "where the remainder is " << (arg % n); return (arg % n) == 0; }` | Defines a matcher `IsDivisibleBy(n)` to match a number divisible by `n`. | -| `MATCHER_P2(IsBetween, a, b, absl::StrCat(negation ? "isn't" : "is", " between ", PrintToString(a), " and ", PrintToString(b))) { return a <= arg && arg <= b; }` | Defines a matcher `IsBetween(a, b)` to match a value in the range [`a`, `b`]. | -<!-- mdformat on --> - -**Notes:** - -1. The `MATCHER*` macros cannot be used inside a function or class. -2. The matcher body must be *purely functional* (i.e. it cannot have any side - effect, and the result must not depend on anything other than the value - being matched and the matcher parameters). -3. You can use `PrintToString(x)` to convert a value `x` of any type to a - string. - -## Actions {#ActionList} - -**Actions** specify what a mock function should do when invoked. - -### Returning a Value - -<!-- mdformat off(no multiline tables) --> -| | | -| :-------------------------------- | :-------------------------------------------- | -| `Return()` | Return from a `void` mock function. | -| `Return(value)` | Return `value`. If the type of `value` is different to the mock function's return type, `value` is converted to the latter type <i>at the time the expectation is set</i>, not when the action is executed. | -| `ReturnArg<N>()` | Return the `N`-th (0-based) argument. | -| `ReturnNew<T>(a1, ..., ak)` | Return `new T(a1, ..., ak)`; a different object is created each time. | -| `ReturnNull()` | Return a null pointer. | -| `ReturnPointee(ptr)` | Return the value pointed to by `ptr`. | -| `ReturnRef(variable)` | Return a reference to `variable`. | -| `ReturnRefOfCopy(value)` | Return a reference to a copy of `value`; the copy lives as long as the action. | -| `ReturnRoundRobin({a1, ..., ak})` | Each call will return the next `ai` in the list, starting at the beginning when the end of the list is reached. | -<!-- mdformat on --> - -### Side Effects - -<!-- mdformat off(no multiline tables) --> -| | | -| :--------------------------------- | :-------------------------------------- | -| `Assign(&variable, value)` | Assign `value` to variable. | -| `DeleteArg<N>()` | Delete the `N`-th (0-based) argument, which must be a pointer. | -| `SaveArg<N>(pointer)` | Save the `N`-th (0-based) argument to `*pointer`. | -| `SaveArgPointee<N>(pointer)` | Save the value pointed to by the `N`-th (0-based) argument to `*pointer`. | -| `SetArgReferee<N>(value)` | Assign `value` to the variable referenced by the `N`-th (0-based) argument. | -| `SetArgPointee<N>(value)` | Assign `value` to the variable pointed by the `N`-th (0-based) argument. | -| `SetArgumentPointee<N>(value)` | Same as `SetArgPointee<N>(value)`. Deprecated. Will be removed in v1.7.0. | -| `SetArrayArgument<N>(first, last)` | Copies the elements in source range [`first`, `last`) to the array pointed to by the `N`-th (0-based) argument, which can be either a pointer or an iterator. The action does not take ownership of the elements in the source range. | -| `SetErrnoAndReturn(error, value)` | Set `errno` to `error` and return `value`. | -| `Throw(exception)` | Throws the given exception, which can be any copyable value. Available since v1.1.0. | -<!-- mdformat on --> - -### Using a Function, Functor, or Lambda as an Action - -In the following, by "callable" we mean a free function, `std::function`, -functor, or lambda. - -<!-- mdformat off(no multiline tables) --> -| | | -| :---------------------------------- | :------------------------------------- | -| `f` | Invoke f with the arguments passed to the mock function, where f is a callable. | -| `Invoke(f)` | Invoke `f` with the arguments passed to the mock function, where `f` can be a global/static function or a functor. | -| `Invoke(object_pointer, &class::method)` | Invoke the method on the object with the arguments passed to the mock function. | -| `InvokeWithoutArgs(f)` | Invoke `f`, which can be a global/static function or a functor. `f` must take no arguments. | -| `InvokeWithoutArgs(object_pointer, &class::method)` | Invoke the method on the object, which takes no arguments. | -| `InvokeArgument<N>(arg1, arg2, ..., argk)` | Invoke the mock function's `N`-th (0-based) argument, which must be a function or a functor, with the `k` arguments. | -<!-- mdformat on --> - -The return value of the invoked function is used as the return value of the -action. - -When defining a callable to be used with `Invoke*()`, you can declare any unused -parameters as `Unused`: - -```cpp -using ::testing::Invoke; -double Distance(Unused, double x, double y) { return sqrt(x*x + y*y); } -... -EXPECT_CALL(mock, Foo("Hi", _, _)).WillOnce(Invoke(Distance)); -``` - -`Invoke(callback)` and `InvokeWithoutArgs(callback)` take ownership of -`callback`, which must be permanent. The type of `callback` must be a base -callback type instead of a derived one, e.g. - -```cpp - BlockingClosure* done = new BlockingClosure; - ... Invoke(done) ...; // This won't compile! - - Closure* done2 = new BlockingClosure; - ... Invoke(done2) ...; // This works. -``` - -In `InvokeArgument<N>(...)`, if an argument needs to be passed by reference, -wrap it inside `std::ref()`. For example, - -```cpp -using ::testing::InvokeArgument; -... -InvokeArgument<2>(5, string("Hi"), std::ref(foo)) -``` - -calls the mock function's #2 argument, passing to it `5` and `string("Hi")` by -value, and `foo` by reference. - -### Default Action - -<!-- mdformat off(no multiline tables) --> -| Matcher | Description | -| :------------ | :----------------------------------------------------- | -| `DoDefault()` | Do the default action (specified by `ON_CALL()` or the built-in one). | -<!-- mdformat on --> - -**Note:** due to technical reasons, `DoDefault()` cannot be used inside a -composite action - trying to do so will result in a run-time error. - -<!-- GOOGLETEST_CM0032 DO NOT DELETE --> - -### Composite Actions - -<!-- mdformat off(no multiline tables) --> -| | | -| :----------------------------- | :------------------------------------------ | -| `DoAll(a1, a2, ..., an)` | Do all actions `a1` to `an` and return the result of `an` in each invocation. The first `n - 1` sub-actions must return void and will receive a readonly view of the arguments. | -| `IgnoreResult(a)` | Perform action `a` and ignore its result. `a` must not return void. | -| `WithArg<N>(a)` | Pass the `N`-th (0-based) argument of the mock function to action `a` and perform it. | -| `WithArgs<N1, N2, ..., Nk>(a)` | Pass the selected (0-based) arguments of the mock function to action `a` and perform it. | -| `WithoutArgs(a)` | Perform action `a` without any arguments. | -<!-- mdformat on --> - -### Defining Actions - -<!-- mdformat off(no multiline tables) --> -| | | -| :--------------------------------- | :-------------------------------------- | -| `ACTION(Sum) { return arg0 + arg1; }` | Defines an action `Sum()` to return the sum of the mock function's argument #0 and #1. | -| `ACTION_P(Plus, n) { return arg0 + n; }` | Defines an action `Plus(n)` to return the sum of the mock function's argument #0 and `n`. | -| `ACTION_Pk(Foo, p1, ..., pk) { statements; }` | Defines a parameterized action `Foo(p1, ..., pk)` to execute the given `statements`. | -<!-- mdformat on --> - -The `ACTION*` macros cannot be used inside a function or class. - -## Cardinalities {#CardinalityList} - -These are used in `Times()` to specify how many times a mock function will be -called: - -<!-- mdformat off(no multiline tables) --> -| | | -| :---------------- | :----------------------------------------------------- | -| `AnyNumber()` | The function can be called any number of times. | -| `AtLeast(n)` | The call is expected at least `n` times. | -| `AtMost(n)` | The call is expected at most `n` times. | -| `Between(m, n)` | The call is expected between `m` and `n` (inclusive) times. | -| `Exactly(n) or n` | The call is expected exactly `n` times. In particular, the call should never happen when `n` is 0. | -<!-- mdformat on --> - -## Expectation Order - -By default, the expectations can be matched in *any* order. If some or all -expectations must be matched in a given order, there are two ways to specify it. -They can be used either independently or together. - -### The After Clause {#AfterClause} - -```cpp -using ::testing::Expectation; -... -Expectation init_x = EXPECT_CALL(foo, InitX()); -Expectation init_y = EXPECT_CALL(foo, InitY()); -EXPECT_CALL(foo, Bar()) - .After(init_x, init_y); -``` - -says that `Bar()` can be called only after both `InitX()` and `InitY()` have -been called. - -If you don't know how many pre-requisites an expectation has when you write it, -you can use an `ExpectationSet` to collect them: - -```cpp -using ::testing::ExpectationSet; -... -ExpectationSet all_inits; -for (int i = 0; i < element_count; i++) { - all_inits += EXPECT_CALL(foo, InitElement(i)); -} -EXPECT_CALL(foo, Bar()) - .After(all_inits); -``` - -says that `Bar()` can be called only after all elements have been initialized -(but we don't care about which elements get initialized before the others). - -Modifying an `ExpectationSet` after using it in an `.After()` doesn't affect the -meaning of the `.After()`. - -### Sequences {#UsingSequences} - -When you have a long chain of sequential expectations, it's easier to specify -the order using **sequences**, which don't require you to given each expectation -in the chain a different name. *All expected calls* in the same sequence must -occur in the order they are specified. - -```cpp -using ::testing::Return; -using ::testing::Sequence; -Sequence s1, s2; -... -EXPECT_CALL(foo, Reset()) - .InSequence(s1, s2) - .WillOnce(Return(true)); -EXPECT_CALL(foo, GetSize()) - .InSequence(s1) - .WillOnce(Return(1)); -EXPECT_CALL(foo, Describe(A<const char*>())) - .InSequence(s2) - .WillOnce(Return("dummy")); -``` - -says that `Reset()` must be called before *both* `GetSize()` *and* `Describe()`, -and the latter two can occur in any order. - -To put many expectations in a sequence conveniently: - -```cpp -using ::testing::InSequence; -{ - InSequence seq; - - EXPECT_CALL(...)...; - EXPECT_CALL(...)...; - ... - EXPECT_CALL(...)...; -} -``` - -says that all expected calls in the scope of `seq` must occur in strict order. -The name `seq` is irrelevant. - -## Verifying and Resetting a Mock - -gMock will verify the expectations on a mock object when it is destructed, or -you can do it earlier: - -```cpp -using ::testing::Mock; -... -// Verifies and removes the expectations on mock_obj; -// returns true if and only if successful. -Mock::VerifyAndClearExpectations(&mock_obj); -... -// Verifies and removes the expectations on mock_obj; -// also removes the default actions set by ON_CALL(); -// returns true if and only if successful. -Mock::VerifyAndClear(&mock_obj); -``` - -You can also tell gMock that a mock object can be leaked and doesn't need to be -verified: - -```cpp -Mock::AllowLeak(&mock_obj); -``` - -## Mock Classes - -gMock defines a convenient mock class template - -```cpp -class MockFunction<R(A1, ..., An)> { - public: - MOCK_METHOD(R, Call, (A1, ..., An)); -}; -``` - -See this [recipe](cook_book.md#using-check-points) for one application of it. - -## Flags - -<!-- mdformat off(no multiline tables) --> -| Flag | Description | -| :----------------------------- | :---------------------------------------- | -| `--gmock_catch_leaked_mocks=0` | Don't report leaked mock objects as failures. | -| `--gmock_verbose=LEVEL` | Sets the default verbosity level (`info`, `warning`, or `error`) of Google Mock messages. | -<!-- mdformat on --> |